"Speak another thing regarding these verses of poetry," said Rabbi Simon. "Not everyone who recites poetry is considered a poet. Rather, anyone who experiences a miracle and recites poetry, it is known that all of their sins are forgiven and they become a new creation. When the Israelites experienced a miracle and recited poetry, all of their sins were forgiven, as it says in Exodus 15:22, 'And Moses led Israel away from the Red Sea.'
This signifies that they were saved from their sins. The Red Sea is also mentioned in Psalm 106:7, 'And they rebelled against the sea at the Red Sea.' Similarly, when Deborah and Barak experienced a miracle and recited poetry, all of their sins were forgiven, as it says in Judges 5:1, 'Then Deborah sang.' And how do we know that their sins were forgiven?
We can infer from what is written afterwards in Judges 6:1, 'And the children of Israel did evil again in the sight of the Lord.' This indicates that their past sins were forgiven, but they committed new sins later. However, God forgave them when they recited poetry. The same is true for David, who experienced a miracle and recited poetry.
How do we know that his sins were forgiven? It says in 2 Samuel 23:1, 'Now these are the last words of David,' indicating that his past sins were forgiven. This teaches us that God forgave his past sins when he recited poetry."...